Don't let your open door policy eat up so much of your time that you end up working until midnight every night. Start scheduling meetings with employees. When they come to your office to talk ask them to schedule a convenient time to meet with you. This will help you minimize interruptions that turn into a three hour talk with an employee and the time you do spend with them will be more productive. Leaders need to stay in touch with employees and scheduling a time to talk will show that you take your employees and their time seriously.